diff -r 73b3e0e095d3 -r 6c8e8747268d server/migractions.py
--- a/server/migractions.py	Fri Mar 25 12:43:57 2011 +0100
+++ b/server/migractions.py	Fri Mar 25 12:51:20 2011 +0100
@@ -1307,20 +1307,32 @@
     # CWProperty handling ######################################################
 
     def cmd_property_value(self, pkey):
-        rql = 'Any V WHERE X is CWProperty, X pkey %(k)s, X value V'
-        rset = self.rqlexec(rql, {'k': pkey}, ask_confirm=False)
+        """retreive the site-wide persistent property value for the given key.
+
+        To get a user specific property value, use appropriate method on CWUser
+        instance.
+        """
+        rset = self.rqlexec(
+            'Any V WHERE X is CWProperty, X pkey %(k)s, X value V, NOT X for_user U',
+            {'k': pkey}, ask_confirm=False)
         return rset[0][0]
 
     def cmd_set_property(self, pkey, value):
+        """set the site-wide persistent property value for the given key to the
+        given value.
+
+        To set a user specific property value, use appropriate method on CWUser
+        instance.
+        """
         value = unicode(value)
         try:
-            prop = self.rqlexec('CWProperty X WHERE X pkey %(k)s', {'k': pkey},
-                                ask_confirm=False).get_entity(0, 0)
+            prop = self.rqlexec(
+                'CWProperty X WHERE X pkey %(k)s, NOT X for_user U',
+                {'k': pkey}, ask_confirm=False).get_entity(0, 0)
         except:
             self.cmd_create_entity('CWProperty', pkey=unicode(pkey), value=value)
         else:
-            self.rqlexec('SET X value %(v)s WHERE X pkey %(k)s',
-                         {'k': pkey, 'v': value}, ask_confirm=False)
+            prop.set_attributes(value=value)
 
     # other data migration commands ###########################################